Heteropora pacifica Borg, 1933

Common name(s): Northern staghorn bryozoan

Synonyms: Heteropora magna? Heteropora pacifica
Phylum Bryozoa (Ectoprocta)
Class Stenolaemata
Suborder Cerioporina
Family Heteroporidae
Heteropora pacifica from 20 m depth, Coffin Rocks
(Photo by: Dave Cowles, July 2005)
Description:   An erect bryozoan colony of inflexible rounded branches up to 5 mm in diameter, often yellowish-green to gray in color, occasionally with lighter or pinkish tips.  The branches often anastomose.  The zooecia are indistinct from one another, distributed evenly around the branches, and their peristomes often protrude above the general surface of the colony.  The apertures of the zooecia are circular and without an operculum or avicularia (photo).  Colony height to 10 cm.

How to Distinguish from Similar Species:  Heteropora magna (considered by many to be another form of this species) is usually colored gray-purple and the branches rarely anastomose.  The zooecia protrude slightly, if at all, above the colony.  An Alaskan species, H. alaskensis (formerly H. pacifica var alaskensis), grows to only 1.6 cm high and has branches 2 mm in diameter.

Geographical Range:   Alaska to Central CA

Depth Range:  Very low intertidal to 27 m.  Mostly subtidal.

Habitat:  Attached to rocks, mainly in areas of brisk water action

Biology/Natural History:  This bryozoan could easily be mistaken for a coral or hydrocoral.  Many consider Heteropora pacifica and H. magna to be simply different forms of the same species.  The tips of the branches evidently have live zooids, and the green color elsewhere may be due to unicelluler algae.



Dichotomous Keys:
  Kozloff 1987, 1996

General References:
  Gotshall, 1994
  Kozloff, 1993
  O'Clair and O'Clair, 1998

Scientific Articles:

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

This photo of a small colony shows some of the individual zooids

This closer view of the colony shows the live zooids at the tip of a branch extending their lophophores.

An underwater photo by Kirt Onthank, July 2007

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)